# \ 

Used as control-space to insert an explicit nonbreaking space, especially when a literal space would be ignored or to force spacing after a control word.

https://texform.dev/latex/commands/-20-

## Metadata

| Field | Value |
| --- | --- |
| Topic | [Spacing](https://texform.dev/latex/topics/spacing) |
| Packages | base, textmacros |
| Allowed mode | math, text |
| Tags | spacing |
| Commonality | medium |
| Kind | prefix |

## Syntax

### base

Argument specification: ``

Used as control-space to insert an explicit nonbreaking space, especially when a literal space would be ignored or to force spacing after a control word.

### textmacros

Argument specification: ``

Used as TeX control-space in text mode to insert a literal space character, especially after a control sequence or when a space must be quoted explicitly inside text macros.

## Common tasks

### How to insert a space after a control word

\ followed by a space is a control space; it keeps a word-like gap after \log.

```latex
\log\ x
```

[Open in Playground](https://play.texform.dev/?input=%5Clog%5C+x)

### How to keep a visible gap between two letters

```latex
a\ b
```

[Open in Playground](https://play.texform.dev/?input=a%5C+b)

## Examples

```latex
a\ b
```

[Open in Playground](https://play.texform.dev/?input=a%5C+b)

```latex
\text{hello\ world}
```

[Open in Playground](https://play.texform.dev/?input=%5Ctext%7Bhello%5C+world%7D)

## Package variants

| Package | Argument specification | Allowed mode | Description |
| --- | --- | --- | --- |
| base |  | math | Used as control-space to insert an explicit nonbreaking space, especially when a literal space would be ignored or to force spacing after a control word. |
| textmacros |  | text | Used as TeX control-space in text mode to insert a literal space character, especially after a control sequence or when a space must be quoted explicitly inside text macros. |

## Renderer support

| Package | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- |
| base | full | full | full |
| textmacros | full | full | full |

## Usage frequency

5.97% of formulas in the measured corpus contain this entry, rank 11 of 263 entries with frequency data.

## In TeXForm

TeXForm parses this entry as prefix syntax; the package determines its argument specification.

### [base/control-space-to-tilde](https://texform.dev/rules/base/control-space-to-tilde)

Rewrite math-mode control space to the canonical active space token.

Level: authoring. Fidelity: render.

```latex
\ 
```

→

```latex
~
```

```latex
a\ b
```

→

```latex
a~b
```

## Equivalent forms

```latex
\space
```

exact. Mapped to the same MathJax parse method and produces the same nonbreaking-space token.

```latex
~
```

exact. The active tilde character is handled by the same parse method in MathJax math mode.

## See also

- [\\{](https://texform.dev/latex/symbols/-7b-)
- [\\}](https://texform.dev/latex/symbols/-7d-)
- [\\~](https://texform.dev/latex/commands/-7e-)
- [\\nobreakspace](https://texform.dev/latex/commands/nobreakspace)
- [\\space](https://texform.dev/latex/commands/space)

## Test cases

### base

| Input | Case | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- | --- |
| \  | Positive: baseline | Pass | Pass | Pass |

### textmacros

| Input | Case | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- | --- |
| \  | Positive: baseline | Pass | Pass | Pass |